Blasting assembly



July 5, 1932. J SWENEHART 1,865,447

BLASTING ASSEMBLY Filed April 25, 1931 INVENTOR (fa/m fiwerze/zart ATTO RNEY Patented July 5, 1932 ,UNITED srAres PATENT? oFFicE Jenn SWENEHART, or WILMINGTON, DELAWARE, ssrenon. T0 Antes. rownnn COM-- PANY, 0F WILMINGTON, DELAWARE, CORPORATION OF. DELAWARE BLAsTme, ASSEMBLY Application filed April 25,

creased convenience in-use, improved protection against moisture, improved economy of consumer time, and elimination of many of the effects. of consumercarelessness and ignorance; i

' Under existing methods a blaster must purchase and be provided with a box of blastingcaps, a roll of fuse, a cap crimper, and means for igniting the fuse. Under my pro osed invention I substitute a single *pac age containing the caps crimped on the fuses under conditions which secure the maximum effective and safe results, each of said fusesbeing provided at its freeend with a waterproofing material or a material which I combines capability of waterproofing with ready inflammability to insure ease of igni: .tion from some simple source, such as a match, for example.

Under existing practice blasting caps are practically always shipped and handled in a metallic box having a slip cover. These boxes do not provide. protection against moisture. Further, these relatively small boxes are easily misplaced; many users do not remove the caps from the boxes ina safe manner and the exposed charge is very sens1t1ve and hazardous under careless handhng.

It is easy to accidentally drop from the box a cap which might be found by children or fothers unfamiliar with its character and its dangerous nature.

Thecommonly employed safety fuse issold in coils wrapped. in paper. Thereare always two open, ends at which the ignitable train 1931. Serial No. 532,912.

maybe damaged: by moisture. The instructions. given by the manufacturers of safety fuses are to out a piece from the end'to eliminate possibly. damaged; fuse, before taking a section for use. Failure to do so may mean misfire, inefficiently exploding'caps or difficulty in igniting the fuse, with considerable resultant hazards. For instance, when a series of rounds are being set off, the operator must not spend-too long a time at each fuse. Further, tightly coiled fuses may be dainaged by unwinding in cold weather. Cap crimpers properly used are essential-for the proper combinationiof. the cap and fuse, yet

. many consumersuse the crimpers improper ly. or havenone at all. whenneeded, using their teeth, a pen knife, a piece of? rock or other hazardous and unsatisfactory measures to crimp the cap on the fuse.

A further source of possible danger resides in the failure. of the user to out the fuse ofl' squarely so that its butt end sets squarely. Very frequently.

on the 1 cap composition. the user cuts the end of: the fuse 'oif at. an

angleand in suchrmanneri that it'seats only.

partiallyon the cap compositions This'frequecntly causes a failure-ofthe charge to ex- 10 e. P It is difiicult to ignite the endof a fuse, evenwhen the fuse is in perfect condition and it is commonipractice for the users to split the end of the fuse :with a pen knife to expose the powder train in an endeavor to bring about. ready ignition. Even without this expedient it is frequently impossible to bring. about: ignition from a single match flame and especiallylis this true ifthe wind is blowing.

It is frequently the case that the blaster must make severalattempts and light several matches before ignition is-effected. This is not so serious a matterwhere only one charge is to be set off, but Where a number of rounds haveto be fired thedelay in effecting ignition compels thehlaster to remain toolong near a previously ignited fuse and has resulted in many serious accidents. In an endeavor to very considerable number of accidents have occurred 'fromsuch devices, the final dyna mite charge exploding before the blaster knew thatthe fuse was ignited. Further, such large masses of flame are in themselves dangerous around explosives.

It is generaly recognizedthat electric blasting caps are safer in transportation and handling than ordinary blasting caps, because of thecushioning effect of the wires. In like manner, with my new assembly, the caps are cushioned in their packages by the presence of and are separated by the fuse.

If achild or ignorant person should find a cap with a fuse tightly aiiixed to it, they would be more impressed with its poten-,

tialities for danger than by the blasting cap alone.

prod 'into the cap with a nail as is often the case, Many of the difiiculties outlined above have been long recognized but the method of use of cap and fuse has remained unchanged. I propose by my present invention to bring about a combination-of conditions which will meet every objection and insure the desirable results above outlined.

,At the blasting factory ther caps a nd fusei i are stored under ideal conditionsunti'l it is desiredto-assemble them. In a dry building proper fuse lengths are cut, ends which have had air exposure being discarded. A flatly cut fuse end is inserted in each cap,.gently but to a snugly seatedfit. Proper crimpers a 'diflicultly breakable and moisture tight union. There still remains an open fuse end. This may be protected by dipping in a sealing compound, as molten tar which is solid when cold. This bead of tar protects against moisture absorption at any time, and when out off exposes a dry fuse end for lighting. Preferably, this fuse end protection isa moisture resistantbomposition which will ignite from the least touch of a match flame and will in turn ignite the fuse. Such compositions may be suspended in nitrocellulose lacquer and applied by dipping the fuse end Suitable, but not limiting. p

- niZe the possibility of causing the bead 9 to in the pasty mass; compositions are e %-25 tetrylpotassium dichiomate 25 %7 5% ammonium picrate.barium nitrate In addition they could not so easily 20 charcoal-potassium chlorate 50 76-50% tetryl-lead peroxide With the inflammable bead applied and dried, further protective dips may be used, such as one or more dips in nitrocellulose lacquer with drying between repeated dips. The protective. dips may extend as far up on the fuse as desired.

An assembly in accordance with the present invention is illustrated in the accompanying drawing wherein 5 designates a conventional blasting cap and 6 a length of conventional safety fuse. The commonly employed safety fuse comprises a sheath of waterproof-material and a core 8 of powder'or'other'suitable ignition train material. An igniting bead 9 "comprising a mass of such volume asto sub-- stantially completely'span the end of the: fuse, and to wholly 'closeand seal the cen tral-channel'in which the core 8 of ignition train 'materlal is located, is secured by its OWIltl-dllQSlVG quality to the outer end of the fuse 6, and preferably the outersend of the. fuse is concaved to receive this mass" of 1gniting bead material. After the lacquer dips 7a have been applied, it will be seen that these lac uer di s; constitute a' water roofin b sheath of inverted cup formation, completely housing andenclosingthe bead .9 and the: outer end of the fuse 6, the material of the sheath so formed being of highly inflammable non-hygroscopic nature. It follows that the least touch of flame thereto will ignite this sheath and igniting bead 9, and the latter is in sufficient volume to substantially span the entire outer end of the fuse and close and seal the powder train against the entry of mois ture; j I

The essentials of the-assembly, viz; cap 5, fuse 6, igniting bead 9, and lacquer or like dip or dips 7a being moisture proof by the nature of the assembly, there is full protection in spite of consumer irregularities. -Ordinary paper cartons may be used for packing and the separate assemblies may be so staggered in packing. that no two caps are in direct contact.

The consumer need only remove an assembly,

While the use of the whole assembly willgive the best results for the reasons stated,

it is apparent that the use of a fuse having a waterproofing and waterproofing bead or ignition bead is desirable whether the Whole assembly be used or not and consequently'it' is to be understood that thatthought alone is within the purview of theinvention. Further, I wish it understood that I recogcomprise a material such as any of the well known safety match compositions adapted to be ignited by friction so that no match need inga moisture proof sheath having an opening formed therethrough, an ignition train in said opening, said sheath having a concaved outer end, an igniting head of highly inflammable material," oval in cross section, seated in the concaved outer end of the fuse with its long axis disposed transversely of said fuse,

said head spanning substantially the entire outer end of the sheath and completely sealing the ignition train opening thereof.

2. A structure as recited in claim 1 in combination with a dip of highly inflammable Waterproof and non-hygroscopic material adhesively secured to the outer end of the sheath,

and said bead, and aiding in holding thelatter in place, substantially as described.

3. A structure as recited in claim 1 wherein said fuse is of a predetermined length and square cut at its inner end, and a blasting cap crimped thereon with the inner end of the fuse in close contact with the charge of the blasting cap, the whole constituting a preformed article of manufacture.

4. In combination, a safety fuse comprising a moisture proof sheath having an opening formed therethrough, an ignition train in said opening, a relatively thick bead of inflammable and adhesive material of such volume and width as to completely cover the said opening of the sheath, the end of the sheath'being made of concaved formation for the reception of said bead, and an adhesve dip of inflammable material which completely enl(Slosas the outer end of the sheath and said 5. A structure as recited in claim 4 wherein the said bead is of a width to span the entire outer end of the sheath.

6. In combination, a safety fuse comprising a moisture proof sheath having an opening formed therethrough, an ignition train in said opening, a relatively thick bead of inflammable and adhesive material of such volume and width as to completely cover the said opening of said sheath, and an adhesive dip of inflammable material which completely incloses the outer end of the sheath and said head, said fuse being of predetermined length and squarecut at its inner end, and a blasting cap crimped thereon with the inner end of the fuse in close contact with the charge of the blasting cap, the Whole constituting a preformed article of manufacture.

7. In combination, a section of safety fuse of a predetermined length having the usual 1gn1t1on train extending centrally therethrough, a head of inflammable and moisture proof material upon the outer end of the fuse,

a sealing dip waterproofing composition covering said bead and the outer end of the safety fuse, a blasting cap upon the inner end of the fuse, the inner end of said fuse being square cut and seated firmly upon the explosive charge of the blasting cap, said blasting cap being crimped upon said fuse prior to shipment and the whole constituting a preformed article of manufacture and explosive assembly.

In testimony whereofI affix my signature.

' JOHN SWENEHART.

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